In a DC steady-state circuit containing an inductor, what is the inductor's impedance behavior?

In a DC steady-state circuit containing an inductor, what is the inductor's impedance behavior?

• A. Open circuit
• B. Short circuit
• C. It has inductive reactance X_L > 0
• D. Infinite resistance

Answer: (B)

In DC steady state, an inductor presents zero impedance to the circuit. This comes from its impedance formula Z_L = j ω L. For direct current, the angular frequency ω is zero, so Z_L = 0. With an ideal inductor, that means there is no voltage drop across it, and the inductor behaves like a short circuit, allowing current to pass freely. In real inductors there is some winding resistance, so it isn’t a perfect zero-ohm path, but the ideal model shows zero impedance for DC steady state.

In DC steady state, an inductor presents zero impedance to the circuit. This comes from its impedance formula Z_L = j ω L. For direct current, the angular frequency ω is zero, so Z_L = 0. With an ideal inductor, that means there is no voltage drop across it, and the inductor behaves like a short circuit, allowing current to pass freely. In real inductors there is some winding resistance, so it isn’t a perfect zero-ohm path, but the ideal model shows zero impedance for DC steady state.